I am planning to unlock new phone, which is currently locked to 3 network. My friend told me that even if I unlock the phone, it would not work with any other sim cards but only with 3 sim. She showed me her 3 sim card and it actually has different chip, bit smaller than mine.
No, if you unlock your Nokia 6700 then you can swap networks...without any problem.To unlock visit Theunlockarena.com and specify the country,locked network.Based on the availability you can get the unlock code along with step by step instructions.Regarding your friend's sim, the sim size comes in 3 types;mini,micro and nano..so your friend might have showed either the mini or nano sim size.